Light chain deposition disease and proximal tubulopathy in two successive kidney allografts.

Light chain proximal tubulopathy (LCPT) is a rare kidney disease associated with plasma cell dyscrasias, characterized by light chain deposits in the proximal tubular cells, with or without crystal formation. We describe an exceptional case of LCPT without crystal formation in a kidney allograft, in a patient who underwent two renal transplants for a light chain deposition disease (LCDD) complicating smoldering myeloma. This is the first description of this association in successive kidney allografts. We concisely describe pathology of LCDD and LCPT and discuss potential pathophysiological mechanisms relating these two conditions.